Adrenocortical carcinoma: Single center experience

Abstract

Objective: Adrenocortical carcinoma is an aggressive endocrine malignancy with an annual incidence of 0.5-2 cases per million. The most important factors that determine prognosis are tumor stage at the time of diagnosis and the success of surgery. However, advanced age, large tumor size, hormone secretion, high Ki-67 index (>10%), tumor necrosis and high mitotic activity are other factors associated with poor prognosis. In the present study, we aimed to evaluate the contribution of the patient and treatment- related factors to the prognosis in adrenocortical carcinoma.

Material and methods: We included 15 adrenocortical carcinoma patients who were followed in our center between 2005 and 2015. The effects of age, gender, tumor size, type of operation, postoperative resection status and adjuvant treatment on disease-free survival and overall survival were analyzed.

Results: Disease-free survival was 23.32±3.69 months and overall survival was 36.60±10.78 months. Gender, tumor size, tumor stage, type of operation, hormonal activity, presence of necrosis, recurrence and development of metastasis were not found to be associated with disease-free survival and overall survival (p>0.05). Postoperatively applied adjuvant treatments including mitotane, chemotherapy and radiotherapy did not significantly affect disease-free survival in our study, but statistically significant increase in overall survival was observed in patients getting adjuvant treatments (p=0.006).

Conclusion: Adrenocortical carcinoma has poor prognosis and short overall survival, and in its clinical course, recurrence and development of metastasis can be commonly observed even after complete resection of the tumor. Therefore, the patients should be evaluated carefully while determining the surgical procedure during the preoperative period, and the operation and post-operative follow-up should be performed in experienced centers. However, due to the positive effects of adjuvant treatments on survival, all patients should be evaluated postoperatively for the necessity of adjuvant treatments, especially mitotane.

Keywords: Adrenocortical carcinoma; chemotherapy; mitotane; surgery.

Figure 1

Treatment algorithm of non-metastatic adrenal carcinoma 1) If Ki67 index can not be measured, then higher proliferative index (>mitoses/5 large field) can be used in the evaluation of risk. 2) In patients who had undergone R2 resection, re-operation should be considered by an experienced surgeon. 3) Tumor diameter less than 8 cm, and lack of evidence of microscopic invasion into tumor capsule are indicators of decreased risk for recurrence.In cases which meet these conditions follow-up may be planned. 4) Individualized treatment (especially in patients who demand aggressive treatment): Ki67 ≥20, in the presence of microscopic invasion to vessels and tumor capsule decision favoring additional radiotherapy directed to tumor bed, if tumor thrombus is seen in vena cava, then decision favoring administration of additional dose of streptozotocin. 5) Re-operation is recommended if complete resection is feasible, and a time interval of less than 12 months passed between primary surgery and recurrence. If this time interval is less than 6 months, since most of the patients would not benefit from resection of the recurrent lesion, systemic treatment is initiated as soon as possible.

Figure 2. a, b

Kaplan-Meier curves demonstrating disease-free survival (a) and total survival (b) rates

Figure 3

Total survival curve in treated, and untreated patients